I am setting up a multiblog. In sub-blogs that mapped on a different domain, permalinks work with only "default" values. They broke if set to other valid values.

My main domain name is abc.com
I have three subdomains: aaa.abc.com, bbb.abc.com, ccc.abc.com
Everything works fine.
Now, I need to map bbb.com to bbb.abc.com (for example).
I've tried two methods: using the MU domain mapping plugin, and following the instructions there.
In both cases, I get the exact same behavior:

Everything seems to work.

Domains are correctly setup and map correctly

Links on blogs work if set to "default" (p=123)

Permalinks on non-mapped sites (ccc.abc.com) work

on domains that are mapped (bbb.com) permalinks break if set to anything but default (yyyy/mm/post_name).

I've read countless threads, tried to modify my htaccess one thousand times, both trying the old markup, the new one, and several custom ones I found on different posts.
I've tried one million different custom permalinks (I'm pretty sure any kind permalink will not work).

this is my configuration for this domain name (the relevant part at least):

All my domains are just wildcard mapped to my root wordpress install, if this is what you are asking. I'll update my question
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XananaxDec 29 '11 at 8:38

What happens if you set the permalinks through network admin > sites > site options?
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George PearceDec 29 '11 at 12:07

The same. But anyway I've come to the conclusion that this isn't a wordpress problem, because I replaced index.php by one of my own that just diplays the server url that was given, and I get the exact same problem. Consequently, I've posted the question in serverfault: serverfault.com/questions/344978/… I keep the question open here though for people that might have the same problem in wordpress specifically.
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XananaxDec 29 '11 at 14:28